SurfIND Series 36 A Common-Mode Chokes

TDK offers their EPCOS SurfIND series of current-compensated ring core double chokes for high currents and surface mounting. With SurfIND, customers who prefer reflow soldering (e.g., sandwich packages in telecom equipment, industrial drives, etc.) but need high-current common-mode chokes (usually large and heavy) can now get an SMD solution. These components can filter common-mode noise for rated currents from 24 A to 36 A at a temperature of +70°C. With additional cooling, even higher currents can be achieved. This is easy to implement, as the top side can serve as a direct interface for a heatsink.

For applications with a voltage of up to 250 V_AC, the nominal inductance ranges from 120 µH to 820 µH across seven variants. With stray inductance of up to 1% of the nominal inductance, these chokes also dampen differential-mode noise. All components meet IEC/EN 60938-2 standards and share a compact footprint of 40 mm x 38 mm (L x W), with heights of 20.7 mm for A types and 22.3 mm for B types. Their typical resistance ranges from 0.78 mΩ to 2.21 mΩ. Rated inductance drops by less than 10% at rated current with DC magnetic bias at +20°C.

SurfIND chokes are mounted on a plastic baseplate with a ferrite core coated in epoxy to insulate it from the windings; both materials are UL 94 V-0 approved. The special design of the connection wiring eliminates the need for adhesives, while self-leading SMD leads ensure easy reflow soldering to PCBs.